The single emerald crab we have is doing an amazing job. The mexican turbos are going crazy on everything else. It's cleaning up nicely. We suffered our first loss unfortunately - the coral beauty angel was swimming erratically from the beginning, bobbing up and down etc.... then we added the clown fish and he began to swim around the tank and eat aggressively. After 7 days he laid down and got super bloated. It appeared the clown fish tried to bring him food for a couple days, it was weird. He didn't make it though. We are now treating the tank with "Medic" water conditioning treatment from a company called Polyplab. I hope this works with any potential parasites.